Noticed this while testing in Mac OS X (El Capitan) with Lulzbot Mini on c.3.2.11
Try to connect to printer when printer is turned off or disconnected from computer. Status will change to "Failed to find a printer via USB"
Turn printer back on and click on connect again but nothing happens (status remains "Failed to find a printer via USB".
If click on "disconnect", status will change to "connection closed" and then user can click on "connect" and succesfully connect to the printer.